The present invention relates to a method and a device for use in the manufacture of fibre pulp from lignocellulose-containing material in the shape of wood chips and the like, which is subjected to disintegration between grinding members in grinding apparatuses in at least two steps. In the grinding apparatus of the first step which also is denominated defibrator, the starting material such as the wood chips is given a disintegration such that the individual fibres in the chips are set free from one another to a substantial degree. The material to be processed then has cotton wool or wadding-like character and is given in the grinding apparatus of the second step, also denominated refiner, an additional disintegration such that the individual fibres are also fibrillated i.e. that their fibrils are separated from each other. The final fibre pulp now has properties suitable for making, e.g. paper, board and the like. The grinding apparatuses may to advantage be of the disc type as e.g. is disclosed in the U.S. Pat. No. 3,212,721.